Requesting ideas for OpenGL project

Hi there OpenGL users.
We have finally ended our semester at university, and we are now suppose to read up on some course content before the exams in January.
One of my courses was Computer Graphic Programming, where we programmed with OpenGL in Unity 3D and experienced with different types of shaders.
As I am not very good at just picking up a book, I prefer much more to begin a small project and learn by getting my hands dirty, though I am not very innovative when it comes to ideas for shader programming projects.

What I seek is a single project idea (or 2-3) which covers these topics: